The present invention relates to an exhaust stack for an off-road work vehicle, and more particularly to combined water trap and aspirator venturi tube structure for a vertical exhaust outlet stack.
Many off-road work vehicles, such as trucks, tractors, off-road equipment, and the like, utilize a vertical exhaust system, in which an exhaust outlet conduit extends vertically from the vehicle. Government regulations designed to reduce engine emissions have required the incorporation of catalytic converters and other moisture-sensitive components in the exhaust system. If such components are mounted in the vertical exhaust system, there is a possibility that water can enter the upper end of the exhaust system and flow downwardly into contact with the equipment, especially the catalytic converter unit, and potentially damage the components. It is known to providing a cover over the upwardly open end of the exhaust outlet to prevent water from entering the exhaust stack or to include a water trap within the vertical outlet stack to collect any water that enters the exhaust stack and direct it away from moisture-sensitiveF components.
Off-road work vehicles may also incorporate venturi tubes disposed within the exhaust outlet stack to produce a vacuum source which may be used for aspiration of moisture which may accumulate as potential contamination in other areas of the engine, particularly the air intake housing. A venturi tube is typically welded into the exhaust stack proximate to the discharge outlet to create a low pressure region in the exhaust stack. An aspirator tube having one end positioned in the low pressure region of the venturi tube and the other end located at a desired location requiring moisture removal provides a low pressure source for aspiration of any accumulated moisture.
Incorporating the above features into a vertical exhaust stack typically requires the addition of two separate structures: a water trap and a venturi tube. The result increases the internal complexity and expense of the exhaust stack as well as the potential for failure. Such increases are often economically intolerable in the competitive small tractor market sector.
It would be a great advantage to provide a single structure for incorporation into a vertical exhaust stack capable of redirecting water entering the stack to protect a catalyst integrated into the exhaust stack and creating the necessary low pressure source to drive a moisture removal aspirator that overcomes the above problems and limitations. Further advantages would be realized by a combined aspirator venturi tube and water trap that is easily incorporated into the vertical exhaust outlet stack of a variety of work vehicles. These and other objects are satisfied by the invention described below.